The controlled release of an active agent from poly(d,l-lactide-co-glycolide) microspheres and the general status of such lactide use is discussed in the article “Controlled Release of a Luteininizing Hormone-Releasing Hormone Analogue from Poly(d,l-lactide-co-glycolide) Microspheres” by L. M. Sanders et al., J. of Pharm. Sci., 73, No. 9, September (1994).
Microencapsulated depot formulations of iloperidone and a poly-glycolide polylactide glucose star polymer are disclosed in U.S. Patent Application Nos. 60/339,036, filed Oct. 30, 2001, and 60/339,037, filed Oct. 30, 2001.
U.S. Pat. No. 5,955,459 describes compositions for treating schizophrenia containing conjugates of a fatty acid and iloperidone. A preferred fatty acid is cis-docosahexanoic acid.
It would be advantageous to develop an iloperidone or its metabolite depot formulation that is as chemically-pure as possible, and which is stable to sterilization procedures, such as gamma irradiation. Furthermore, the depot formulation should provide a reliable, reproducible and constant plasma concentration profile of iloperidone or its metabolite following administration to a patient.